# The Heart

The heart is a muscular structure with four chambers including two atria, which are the filling chambers and two ventricles, which are the pumping chambers.
心脏是一种肌肉结构，有四个腔室，包括两个充血腔的心房和两个泵血腔的心室。^[1]

The venous blood is drained from the body to the right chambers of the heart, then oxygenated in the lungs and ejected to the entire body by the left chambers of the heart.
静脉血从身体流入心脏的右室，然后在肺中充氧，并通过心脏的左室喷射到全身。

The human heart has four valves (flaps made of tissue) that control the direction of blood flow in the circulation. 人类心脏有四个瓣膜 (由组织构成的皮瓣)，控制血液在循环中的流动方向。
Normal valves act like a system of one-way doors, which assures unidirectional blood flow through the various chambers of the heart.
正常的瓣膜就像一个单向阀门，保证血液在心脏的各个腔室中单向流动。
The aortic and mitral valves are part of the "left" heart and control the flow of oxygen-rich blood from the lungs to the body, while the pulmonic and tricuspid valves are part of the "right" heart and control the flow of oxygen-depleted blood from the body to the lungs.
主动脉瓣和二尖瓣是 “左” 心的一部分，控制富氧血液从肺部流向身体，而肺动脉瓣和三尖瓣是 “右” 心的一部分，控制缺氧血液从身体流向肺部。

The aortic valve lies between the left ventricular chamber and aorta, preventing blood from leaking back into the left ventricle after it has been ejected into the circulation.
主动脉瓣位于左心室和主动脉之间，防止血液被排入循环后漏回左心室。
The mitral valve lies between the left atrium and left ventricle preventing blood from leaking back into the left atrium during ejection (systole).
二尖瓣位于左心房和左心室之间，防止血液在射血 (收缩) 时回流到左心房。
Similarly on the right side, the pulmonic valve separates the right ventricle from the pulmonary artery, whereas the tricuspid valve separates the right ventricle from the right atrium.
同样，在右侧，肺动脉瓣将右心室与肺动脉分开，而三尖瓣将右心室与右心房分开。

The normal mitral valve opens when the left ventricle relaxes (diastole) allowing blood from the left atrium to fill the decompressed left ventricle.
正常的二尖瓣在左心室松弛 (舒张) 时打开，使左心房的血液充盈减压的左心室。
When the left ventricle contracts (systole), the increase in pressure within the ventricle causes the valve to close, preventing blood from leaking into the left atrium and assuring that all of the blood leaving the left ventricle (the stroke volume) is ejected through the aortic valve into the aorta and to the body.
当左心室收缩 (收缩) 时，心室内压力的增加导致瓣膜关闭，防止血液泄漏到左心房，并确保所有离开左心室的血液 (每搏量) 都通过主动脉瓣排入主动脉和身体。
Proper function of the valve is dependent on a complex interplay between the annulus, leaflets and subvalvular apparatus.
瓣膜的正常功能依赖于瓣环、瓣叶和瓣下结构之间复杂的相互作用。

Long-standing mitral regurgitation due to mitral valve prolapse is well established as a significant cause of cardiovascular morbidity and mortality ^{[2] [3]}, with surgical intervention often required in patients with severe regurgitation to preserve life expectancy in affected patients.
长期存在的二尖瓣脱垂所致的二尖瓣反流是心血管疾病发病率和死亡率的重要原因。严重反流的患者通常需要手术干预，以保护受影响患者的预期寿命。
Mitral valve repair is now well established and is applicable in practically all patients with clinically significant mitral valve prolapse due to degenerative mitral-valve disease ^{[4] [5]}.
二尖瓣修复术现在已经很成熟，几乎适用于所有临床上因二尖瓣退行性疾病而导致的二尖瓣脱垂的患者。
Valve repair offers a distinct event-free survival advantage compared with replacement with a bioprosthetic or mechanical valve ^{[6] [7] [8]}.
与生物瓣膜或机械瓣膜置换相比，瓣膜修复提供了一个明显的无事件生存优势。

# Leaflets 瓣叶

The mitral valve has two leaflets.
二尖瓣有两个瓣叶。
The anterior leaflet has a semi-circular shape and attaches to two fifths of the annular circumference.
前叶呈半圆形，附着在瓣环的五分之二区域。
There is continuity between the anterior leaflet of the mitral valve and the left and non-coronary cusp of the neighboring aortic valve, referred to as the aortic-mitral curtain.
二尖瓣的前叶与相邻主动脉瓣的左冠瓣、无冠瓣瓣叶之间有连续性，称为主动脉瓣 - 二尖瓣幕帘。
These two components of the aorto-mitral curtain are on two separate anatomical planes, situated at an angle of $120 ^{\circ}$ which corresponds to the planes of the aortic and mitral annulus respectively.
主动脉瓣 - 二尖瓣幕帘的这两个部分位于两个独立的解剖平面上，夹角为 $120 ^{\circ}$ ，分别对应于主动脉瓣环和二尖瓣环的平面。
The free edge of the anterior leaflet is usually continuous, without indentations.
前叶的游离缘通常是连续的，没有凹痕。
The lack of redundancy of this leaflet along its margin must be taken into consideration in the setting of anterior leaflet prolapse as only small areas of leaflet can be safely resected.
在前叶脱垂的情况下，必须考虑到小叶边缘缺乏冗余，因为只有小面积的小叶可以安全切除。
The motion of the anterior leaflet also defines an important boundary between the inflow (during diastole) and outflow (during systole) tracts of the left ventricle.
前叶的运动也定义了左心室流入 (舒张期) 和流出 (收缩期) 的重要边界。

The posterior leaflet of the mitral valve has a quadrangular shape and is attached to approximately three fifths of the annular circumference.
二尖瓣后叶呈四边形，附着在瓣环的五分之三区域。
The posterior leaflet typically has two well defined indentations which divides the leaflet into three individual scallops identified as P1 (anterior or medial scallop), P2 (middle scallop), and P3 (posterior or lateral scallop).
后叶通常有两个明确的切迹，将其分为三个独立的节段，分别是 P1 (前或内侧段)、P2 (中间段) 和 P3 (后或外侧段)。
The three corresponding segments of the anterior leaflet are A1 (anterior segment), A2 (middle segment), and A3 (posterior segment)^[9].
前叶与之相对应的三个节段分别为 A1 (前节)，A2 (中节)，A3 (后节)
This nomenclature is an important tool to describe specific anatomic segmental anatomy between echocardiographer and surgeon.
这一术语是超声心动图医师和外科医生描述特定解剖节段解剖学的重要工具。Indentations aid in posterior leaflet opening during diastole.
切迹有助于舒张期后小叶张开。
They also imply redundancy to the margin of the posterior leaflet, particularly in the setting of prolapse which triggers a process leading to excess tissue in the prolapsing segment, which therefore allows more aggressive resection compared to the anterior leaflet.
切迹还意味着后叶边缘的冗余，特别是在脱垂的情况下，这会导致脱垂段中多余组织的过程，因此与前叶相比，这允许更积极的切除。
The height of the posterior leaflet is less than the anterior leaflet, however, both leaflets have similar surface areas.
后叶的高度小于前叶，但是，两个叶有相似的表面积。

# Commissures

The commissures define a distinct area where the anterior and posterior leaflets come together at their insertion into the annulus. Sometimes the commissures exist as well defined leaflet segments, but more often this area is a subtle structure, and can be identified using two anatomic landmarks: the axis of corresponding papillary muscles and the commissural chordae, which have a specific fan-like configuration. Several millimeters of valvular tissue separates the free edge of the commissures from the annulus. This area must be respected when dealing with prolapse of a commissure and the corresponding anterior and posterior leaflet segment (P3 and A3) by resection, for example, or a residual regurgitation will occur from this region.